Blackcherokee290

Hey guys...

My jeep: 2000 XJ Classic, I6 4.0L, 4x4, 172k miles.

Just curious if anybody has thoughts on this ac issue....If I drive normally and go over 2k rpm for longer than an instant (while it's hot out), the ac stops working until the engine is shut off and allowed to sit for awhile.

If I drive like a grandma the ac will get warm on acceleration then get cold as rpms drop back down.

Just looking for some advice on where to start. Thanks!

QuickNDirty

Stuck blend gate?

Blackcherokee290

Not a bad idea, could be vacuum has to bleed off? I have never considered the blend door could get stuck.....but if it did how does it change the air temp if its not moving? Like doesent the blend default to defrost (where the ac compressor is on anyway)?

Appreciate the response tho quickNDirty

QuickNDirty

It's not my specialty, but RPM dependent AC function makes me think the issue may be in that area somewhere.

If the door is partially open but you're not stressing the systems which need cooling, then your cold air may overpower the hot air coming off the core and your mixture will be more cold than hot. However, when you're rolling down the highway and components start heating up the coolant in the system, the air off the core increases in temperature and the hot air side starts to overpower the cold air side, so your mixture is more warm than more cold.

Blackcherokee290

Alright folks, well the air conditioning was going in and out my entire trip, seemingly getting colder on accel (wtf?) and weaker on deccel. I got pissed off (sears had just evac the system and recharged it then told me the compressor and everything was fine) and left the AC selector on AC mode since it was a few deg cooler than ambient (110). Then the compressor seized up just as I left death valley (omw thru to nevada). Had to get a tow to the nearest town where a relative brought down a compressor bypass pulley.

I had a sears in nevada evac it, I replaced the dryer and compressor, theres no leaks but the compressor clutch will NOT engage.

I would look at QuickNDirtys ideas but without the compressor clutch engaging theres not much I can do.

Ideas???

JPXJMOAB

High pressure cutoff? Are you sure you have the correct amount of refrigerant?

Blackcherokee290

Thats actually not a bad thing to just replace. I am pretty sure that theres the correct amount of refrigerant since sears did it (although in my experience that dont mean much )

The compressor wasnt engaging cause sears never reconnected the freaking wiring harness to it. I didnt have a chance to pop the hood when I picked it up. They also did not replace the bolt on the accumulator with the correct one (I explicitly told them to replace it since I didnt have the right socket).